3,745 research outputs found
Anode materials for electrochemical waste destruction
Electrochemical Oxidation (ECO) offers promise as a low-temperature, atmospheric pressure method for safe destruction of hazardous organic chemical wastes in water. Anode materials tend to suffer corrosion in the intensely oxidizing environment of the ECO cell. There is a need for cheaper, more resistant materials. In this experiment, a system is described for testing anode materials, with examples of several common anodes such as stainless steel, graphite, and platinized titanium. The ECO system is simple and safe to operate and the experiment can easily be expanded in scope to study the effects of different solutions, temperatures, and organic materials
Confined coherence in quasi-one-dimensional metals
We present a functional renormalization group calculation of the effect of
strong interactions on the shape of the Fermi surface of weakly coupled
metallic chains. In the regime where the bare interchain hopping is small, we
show that scattering processes involving large momentum transfers perpendicular
to the chains can completely destroy the warping of the true Fermi surface,
leading to a confined state where the renormalized interchain hopping vanishes
and a coherent motion perpendicular to the chains is impossible.Comment: 4 RevTex pages, 5 figures,final version as published by PR
A Sourcing Strategy for Active Pharmaceutical Ingredients (APIs)
We describe the development over the past decade of a sourcing strategy within the Roche group for active pharmaceutical ingredients and the intermediates used in their manufacture. The roles of certain production sites have been modified in the light of this strategy. Before sourcing decisions are taken, criteria including life-cycle phase of the product, whether the step under review comes early or late in the synthesis, protection of proprietary know-how, quantities needed, speed, available capacity and full production costs are systematically evaluated on a case-by-case basis. For each sourcing decision, different scenarios are compared, in particular that of in-house vs. external production. In future, we envisage intensified competition both among Contract Manufacturing Organisations (CMOs) for business from large pharma concerns and among the large pharma concerns themselves for the capacity available from the CMOs. In consequence, the large pharma concerns will have to continually adapt their sourcing strategies to the changing environment and will have to have available flexible production plants and organisations if they wish to maintain a viable in-house alternative to contract manufacture
Determination of 2beta_s in B_s -> J/psi K^+ K^- Decays in the Presence of a K^+K^- S-Wave Contribution
We present the complete differential decay rates for the process B_s -> J/psi
K^+ K^- including S-wave and P-wave angular momentum states for the K^+ K^-
meson pair. We examine the effect of an S-wave component on the determination
of the CP violating phase 2beta_s. Data from the B-factories indicate that an
S-wave component of about 10% may be expected in the phi(1020) resonance
region. We find that if this contribution is ignored in the analysis it could
cause a bias in the measured value of 2beta_s towards zero of the order of 10%.
When including the K^+K^- S-wave component we observe an increase in the
statistical error on 2beta_s by less than 15%. We also point out the
possibility of measuring the sign of cos2beta_s by using the interference
between the K^+K^- S-wave and P-wave amplitudes to resolve the strong phase
ambiguity. We conclude that the S-wave component can be properly taken into
account in the analysis.Comment: 11 pages, 6 figure
A Testing Strategy for Abstract Classes [Draft]
One of the characteristics of the increasingly widespread use of object-oriented libraries and the resulting
intensive use of inheritance is the proliferation of dependencies on abstract classes. Since abstract classes
cannot be instantiated, they cannot be tested in isolation using standard execution-based testing strategies.
A standard approach to testing abstract classes is to instantiate a concrete descendant class and test the
features that are inherited.
This paper presents a structured approach that supports the testing of features in abstract classes,
paying particular attention to ensuring that the features tested are those defined in the abstract class. Two
empirical studies are performed on a suite of large Java programs and the results presented. The first study
analyzes the role of abstract classes from a testing perspective. The second study investigates the impact
of the testing strategy on the programs in this suite to demonstrate its feasibility and to comment on the
pragmatics of its use
The abstract boundary---a new approach to singularities of manifolds
A new scheme is proposed for dealing with the problem of singularities in
General Relativity. The proposal is, however, much more general than this. It
can be used to deal with manifolds of any dimension which are endowed with
nothing more than an affine connection, and requires a family \calc\ of curves
satisfying a {\em bounded parameter property} to be specified at the outset.
All affinely parametrised geodesics are usually included in this family, but
different choices of family \calc\ will in general lead to different
singularity structures. Our key notion is the {\em abstract boundary\/} or {\em
-boundary\/} of a manifold, which is defined for any manifold \calm\ and is
independent of both the affine connection and the chosen family \calc\ of
curves. The -boundary is made up of equivalence classes of boundary points
of \calm\ in all possible open embeddings. It is shown that for a
pseudo-Riemannian manifold (\calm,g) with a specified family \calc\ of
curves, the abstract boundary points can then be split up into four main
categories---regular, points at infinity, unapproachable points and
singularities. Precise definitions are also provided for the notions of a {\em
removable singularity} and a {\em directional singularity}. The
pseudo-Riemannian manifold will be said to be singularity-free if its abstract
boundary contains no singularities. The scheme passes a number of tests
required of any theory of singularities. For instance, it is shown that all
compact manifolds are singularity-free, irrespective of the metric and chosen
family \calc.Comment: 40 pages (amslatex) + 5 uuencoded figures (A postscript version is
also available on http://einstein.anu.edu.au/), CMA Maths. Research Report
No. MRR028-9
Effect of two different participant information sheets on recruitment to a falls trial:an embedded randomised recruitment trial
Background/Aims: Recruitment to trials of intervention for older people who fall is challenging. Evidence suggests that the word falls has negative connotations for older people, and this may present a barrier to engaging with trials in this area. We therefore tested whether a participant information sheet that minimised reference to falls could improve recruitment rates. Methods: We conducted a study within a trial, embedded within a randomised controlled trial of vitamin K versus placebo to improve postural sway in patients aged 65 and over with a history of falls. Potential participants were identified from primary care lists in 14 practices and were randomised to receive either a standard participant information sheet or an information sheet minimising use of the word falls, instead focussing on maintenance of health, fitness and balance. The primary outcome for this embedded trial was the proportion of responses expressing interest in participating received in each arm. Secondary outcomes were the proportion of those contacted attending a screening visit, consenting at screening, and the proportion contacted who were randomised into the main trial. Results: In all, 4145 invitations were sent, with an overall response rate of 444 (10.7%). In all, 2148 individuals received the new information sheet (minimising reference to falls); 1997 received the standard information sheet. There was no statistically significant difference in response rate between those individuals sent the new information sheet and those sent the standard information sheet (10.1% vs 11.4%; difference 1.3% (95% confidence interval -0.6% to 3.2%); p = 0.19). Similarly, we found no statistically significant difference between the percentage of those who attended and consented at screening in the two groups (2.1% vs 2.7%; difference 0.6% (95% confidence interval: -0.4% to 1.6%); p = 0.20), and no statistically significant difference between the percentage randomised in the two groups (2.0% vs 2.6%; difference 0.6% (95% confidence interval -0.4% to 1.6%); p = 0.20). Conclusions: Use of a participant information sheet minimising reference to falls did not lead to a greater response rate in this trial targeting older people with a history of falls.</p
Representation of Maximally Regular Textures in Human Visual Cortex
This research was supported by National Science Foundation INSPIRE Grant 1248076, which was awarded to Y.L. and A.M.N.Peer reviewedPublisher PD
The Massive and Distant Clusters of WISE Survey V: Extended Radio Sources in Massive Galaxy Clusters at z~1
We present the results from a pilot study with the Karl G. Jansky Very Large
Array (JVLA) to determine the radio morphologies of extended radio sources and
the properties of their host-galaxies in 10 massive galaxy clusters at z~1, an
epoch in which clusters are assembling rapidly. These clusters are drawn from a
parent sample of WISE-selected galaxy clusters that were cross-correlated with
the VLA Faint Images of the Radio Sky at Twenty-Centimeters survey (FIRST) to
identify extended radio sources within 1 of the cluster centers. Out
of the ten targeted sources, six are FR II sources, one is an FR I source, and
three sources have undetermined morphologies. Eight radio sources have
associated Spitzer data, 75% presenting infrared counterparts. A majority of
these counterparts are consistent with being massive galaxies. The angular
extent of the FR sources exhibits a strong correlation with the cluster-centric
radius, which warrants further investigation with a larger sample.Comment: accepted to Ap
Estimating Soil Moisture Under Low Frequency Surface Irrigation Using Crop Water Stress Index
The present study investigated the relationship between the crop water stress index (CWSI) and soil moisture for surface irrigated cotton (Gossypium hirsutum, Delta Pine 90b) at Maricopa, Arizona during the 1998 season. The CWSI was linked to soil moisture through the water stress coefficient Ks that accounts for reduced crop evapotranspiration when there is a shortage of soil water. A stress recovery coefficient Krec was introduced to account for reduced crop evapotranspiration as the crop recovered from water stress after irrigation events. A soil water stress index (SWSI) was derived in terms of Ks and Krec . The SWSI compared reasonably well to the CWSI, but atmospheric stability correction for the CWSI did not improve comparisons. When the CWSI was substituted into the SWSI formulation, it gave good prediction of soil moisture depletion (fDEP; when to irrigate) and depth of root zone depletion (Dr ; how much to irrigate). Disagreement was greatest for fDEP\u3c0.6 because cotton is less sensitive to water stress in this range
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